The present invention relates to a conveyance system for use in conveying various articles while supporting them.
As such a conveyance system, for example, the configuration disclosed in Japanese Patent Laid-Open No. 10-111719 is conventionally provided. This conventional configuration is provided with conveying trucks supported and guided along a main track and a branching track. Each of the tracks comprises a bottom wall, a right and a left side walls, and a top wall, and is shaped like a duct by forming a slit in a width-wise center of the top wall, a slit extending along a longitudinal direction. At least at a branching point, a guide along the main track and a guide along the branching track are provided. Further, the conveying trucks are each provided with a guide member following the guides and a directing mechanism for directing the guide member to one of the guides.
The guides comprise guide rails made of a magnetic body and extending along the main track and the branching track, respectively. The guide member comprises a magnetic roller which is directed to either one of the guide rails via an arm or the like.
With the above conventional form, however, the main and branching tracks must be provided with separate guide rails made of a magnetic body. This is cumbersome in assembling or constructing this form. Further, since the main and branching tracks are shaped like ducts, dust or the like collects on the bottom walls of the tracks, which cannot be cleaned easily. Accordingly, it is not easy to employ this conventional form cannot for clean rooms, where clean air is blown downward.
Furthermore, layouts that enable branching and juncture are limited. For example, it is difficult to provide a layout in which the tracks extend in parallel and in which the conveying trucks are shifted between the tracks. As a construction in which the conveying trucks are shifted between the tracks, a swinging table form disclosed in Japanese Patent Laid-Open No. 11-222122 is provided. This invention, however, requires a complicated structure and also requires the conveying truck to stop running between the tracks.
Further, since the main and branching tracks are shaped like ducts, for example, formation of a loop line requires separate exclusive parts to be prepared for a linear portion and a curve portion. In particular, the track of the curve portion is expensive.
A first object of the present invention is to provide a conveyance system constructed so that linear path portions and a branching-and-joining path portion are formed by rail apparatuses in which dust or the like is difficult to collect, wherein a simple structure is added to the rail apparatus arranged in a branching-and-joining section to achieve branching and juncture without any limitations on the layout, thereby realizing effective and flexible conveyance.
A second object of the present invention is to provide a conveyance system constructed so that a fixed path and a branching-and-joining path are formed by rail apparatuses in which dust or the like is difficult to collect, wherein moving bodies can be smoothly moved between the fixed path and the branching-and-joining path for branching and juncture, and wherein curve portions can be formed easily.
To attain the first object, the present invention provides a conveyance system comprising rail apparatuses and moving bodies which are supported and guided by the rail apparatuses so as to move freely on a fixed path, characterized in that: each of the rail apparatuses comprises a lateral pair of rail members each having an upward wheel supporting surface and an inward roller guide surface formed thereon; the fixed path comprises linear path portions and a branching-and-joining path portion; a branching-and-joining section formed by said path portions are provided with linear-side guide members extending along the linear path portions and a branching-and-joining-side guide member extending along the branching-and-joining path portion; and the moving bodies are each provided with wheels supported and guided on the wheel supporting surface, side guide rollers guided on the roller guide surface, and a direction restricting member guided by sideward guide sections of the guide members, the direction restricting member being driven by lateral-movement means to move in a lateral direction between a location corresponding to the linear-side guide member and a location corresponding to the branching-and-joining-side guide member.
With the above configuration of the present invention, the moving bodies can be stably moved and guided by the rail apparatus by supporting and guiding the group of wheels on the wheel supporting surface so as to roll thereon and guiding the side guide roller on the roller guide surface. In this case, the rail apparatus may have a space formed between the lateral pair of rail members along the entire length thereof, and a vertical-penetration portion formed by this space allows air to flow without being hindered, thereby enabling this conveyance system to be suitably employed even for clean rooms where clean air is blown downward.
When the moving body on the linear path portion is moved thereon without being branched or joined to the branching-and-joining path portion, the lateral-movement means may be used to move the direction restricting member away from the branching-and-joining path portion. Then, the direction restricting member can be guided by the guide section of the linear-side guide member, and the moving body can be stably moved straight by the linear path portion without moving into the branching-and-joining path portion.
On the other hand, when the moving body on the linear path portion is branched and joined to the branching-and-joining section, the lateral-movement means may be used to move the direction restricting member to the branching-and-joining path portion. Then, the direction restricting member can be guided by the guide section of the branching-and-joining-side guide member, and the moving body can be branched and moved smoothly and reliably to the branching-and-joining path portion.
In the branching-and-joining section, one of the wheels, rolling on the wheel supporting surface of the rail members, is rolled so as to move across the space between the rail members. Accordingly, this wheel falls into the space, and the weight of the moving body serves to generate a moment around the wheel on the other wheel supporting surface, thus inclining the moving body. At this time, the direction restricting member is guided by the sideward guide member, so that the moment on the moving body can be accommodated to restrict the direction of the moving body, while hindering its inclination. As a result, the above wheel can move across the space stably without falling into it.
As described above, according to the present invention, the conveyance system is constructed so that the linear path portions and the branching-and-joining path portion are formed by the rail apparatus in which dust or the like is difficult to collect, but the simple structure is added to the rail apparatus arranged in the branching-and-joining section to realize branching and juncture without any limitations to the layout, thereby achieving effective and flexible conveyance.
According to a first embodiment of the conveyance system of the present invention, the branching-and-joining path portion is arranged between a pair of parallel linear path portions, linear-side guide members of both linear path portions have linear guide sections formed outside parallel portions of the linear-side guide members and a branching-and-joining guide sections formed inside the parallel portions, the branching-and-joining-side guide member comprises a branching-side guide member and a joining-side guide member which are severed from each other, and a branching-side guide section and a joining-side guide section which are extended from the branching-and-joining-side guide member are formed to extend in different directions, and there is a severed section in which the direction restricting member moved along the branching-side guide section is guided to the joining-side guide section.
According to the first embodiment, when the moving body is moved along the linear path portion without being branched or joined to the branching-and-joining path portion, the direction restricting member is guided by the linear-side guide section of the linear-side guide member, thereby enabling the moving body to move straight along the linear path portion.
On the other hand, when the moving body on one of the linear path portions is branched and joined to the branching-and-joining path portion, it can be moved to the branching-and-joining path portion for juncture by guiding the direction restricting member of the moving body from the branching-and-joining-side guide section of the linear-side guide member to the branching-side guide section of the branching-side guide member. Then, when the direction restricting member is guided by the branching-side guide section, the moving body can be moved to the other linear path portion by allowing the direction restricting member to be guided by the joining-side guide section of the joining-side guide member and then guiding the direction restricting member to the branching-and-joining-side guide section of the linear-side guide member.
Thus, the moving body can be shifted smoothly and reliably between the parallel linear path portions, thus achieving branching and juncture with lesser limitations to the layout.
According to a second embodiment of the conveyance system of the present invention, the direction restricting member is provided via a support so as to move freely in the lateral direction, and lateral-movement means comprises a driving section and a drive transmitting section for moving the support in the lateral direction in response to forward and backward driving effected by the driving section, the drive transmitting section including a device for connecting or disconnecting a transmission path.
According to the second embodiment, the direction restricting member can be moved in the lateral direction by causing the driving section of the lateral-movement means to effect the forward and backward driving so as to cause the connecting and disconnecting device to move the support in the lateral direction via the drive transmitting section in a connected state. In this manner, the transmission path can be made free by moving the direction restricting member in the lateral direction and then disconnecting the connecting and disconnecting device. Accordingly, while the direction restricting member is being guided by the guide members, the lateral movement of the direction restricting member need not be controlled. Consequently, the direction restricting member can be moved smoothly in the lateral direction together with the support.
According to a third embodiment of the conveyance system of the present invention, attracting means is provided for holding the support which has reached a lateral-movement limit location.
According to the third embodiment, after the lateral movement, the support can be held (locked) at the lateral-movement limit location through an attracting action effected by the attracting means. By automatically clearing the attraction effected by the attracting means, the direction restricting member can be smoothly guided and moved by the guide member in the lateral direction together with the support.
To attain the above described second object, the present invention provides a conveyance system comprising rail apparatuses and moving bodies which are supported and guided by the rail apparatuses so as to move freely on a fixed path, characterized in that: the rail apparatuses each comprises a lateral pair of rail members disposed to form a space therebetween, the rail members being each formed with an upward wheel supporting surface and an inward roll guide surface; in a branching-and-joining section leading to the branching-and-joining path which is branched and joined with respect to the fixed path, one of the lateral pair of rail members which is located on the side of the branching-and-joining path is severed to leave a space, and the rail members on the side of the branching-and-joining path are disposed to be contiguous to each severed end; the branching-and-joining section includes a fixed-path-side guide member extending along the fixed path and a branching-and-joining-side guide member extending along the branching-and-joining path; each of the moving bodies includes wheels supported and guided on the wheel supporting surface, side guide rollers guided on the roller guide surface, and a direction restricting member guided by sideward guide sections of the guide members; the direction restricting member is driven by lateral-movement means to move freely in a lateral direction between a location corresponding to the fixed-path-side guide member and a location corresponding to the branching-and-joining-side guide member; and the wheel on the side of the space floats over the wheel supporting surface when the direction restricting member is being guided by the guide member in the branching-and-joining section.
With the above configuration of the present invention, the moving bodies can be stably moved and guided by the rail apparatuses by supporting and guiding the group of wheels on the wheel supporting surface to roll thereon and guiding the side guide roller on the roller guide surface. In this case, the rail apparatus can form a space between the lateral pair of rail members along the entire length thereof, and a vertical-penetration portion formed by this space allows air to flow without being hindered, thereby enabling this conveyance system to be suitably employed even for clean rooms where clean air is blown downward.
Furthermore, the lateral pair of rail members are simple and small enough to be bent with ease to have a minimum cross section required for a functional purpose of the conveyance system. Consequently, no specific rail members are required as rail members for curve paths, but linear rail members can be bent and used for the curve paths, thereby reducing the weight of the entire rail apparatuses and substantially reducing costs.
When the moving body on the fixed path portion is moved without being branched to the branching-and-joining path portion, lateral-movement means may be used to move the direction restricting member away from the branching-and-joining path portion. Then, the direction restricting member can be guided by the guide section of the fixed-side guide member, and the moving body can be stably moved straight along the fixed path without moving into the branching-and-joining path portion.
On the other hand, when the moving body on the fixed path is branched and joined to the branching path or the joining path, the lateral-movement means may be used to move the direction restricting member to the branching-and-joining path. Then, the direction restricting member can be guided by the guide section of the branching-and-joining-side guide member, and the moving body can always be moved smoothly and reliably from the fixed path to the branching path for branching or from the joining path to the fixed path.
Furthermore, in the branching-and-joining section, one of the wheels, rolling on the wheel supporting surface of the rail member, is rolled to move across the space between the rail members. Accordingly, this wheel falls into the space, and the weight of the moving body serves to generate a moment around the wheel on the other wheel supporting surface, thus inclining the moving body. At this time, the direction restricting member is guided by the sideward guide member of the branching-and-joining-side guide member, so that the wheel in the space can be floated over the wheel supporting surface. Consequently, the moment on the moving body can be accommodated to restrict the direction of the moving body, while hindering its inclination. As a result, the above wheel can move across the space stably without falling into it.
As described above, according to the present invention, the conveyance system is configured so that the linear path portions and the branching-and-joining path portion are formed by the rail apparatus in which dust or the like is difficult to collect, but the simple structure is added to the rail apparatus arranged in the branching-and-joining section to realize branching and juncture without any limitations to the layout, thereby achieving effective and flexible conveyance.
According to a preferred embodiment of the conveyance system of the present invention, the wheel on the side opposite to the space is supported on the wheel supporting surface, and the direction restricting member is guided by the guide member. Consequently, the moving body is inclined in the lateral direction to cause the wheel on the side of the space to float over the wheel supporting surface.
According to this preferred embodiment, the wheel on the side opposite to the space is supported on the wheel supporting surface, and the direction restricting member is guided by the sideward guide section of the branching-and-joining-side guide member. Accordingly, the moving body is guided while being supported at two points, thereby enabling the wheel on the side of the space to float over the wheel supporting surface, while allowing the downward moment on the moving body to be accommodated.
According to another preferred embodiment of the conveyance system of the present invention, at least a portion of the guide member is formed to be thick enough to receive the moving body while inclining it in the lateral member.
According to this preferred embodiment, with a simple construction in which the guide member has a thickened portion formed therein (a simple construction in an improved form), the moving body can be received while being inclined in the lateral direction, and a sufficient receiving strength is ensured.